Automatic slide projector



J. ANTOS AUTOMATIC SLIDE PROJECTOR April 11, 1950 9 Sheets-Sheet 1 Filed June 25, 1945 J. ANTOS AUTOMATIC SLIDE PROJECTOR April 11, 1950 9 Sheets-Sheet 2 Filed June 25, 1945 III! III April 11, 1950 J. ANTOS 2,503,239

AUTOMATIC SLIDE PROJECTOR Filed June 25, 1945 9 Sheets-Sheet 3 lIl'Il 8: n llllllllll Invenor April 11, 1950 J. ANTOS 2,503,239

AUTOMATIC SLIDE PROJECTOR Filed June 25, 1945 9 Sheets-Sheet 4 April 11, 1950 J. ANTOS 2,503,239

' AUTOMATIC SLIDE PROJECTOR Filed June 25, 1945 9 Sheets-Sheet 5 Invenior April' 11, 1950 J. ANTOS AUTOMATIC suns: PROJECTOR 9 Sheets-Sheet 6 Filed June 25, 1945 In venl-or April 11, 1950 J. ANTOS 2,503,239

AUTOMATIC SLIDE PROJECTOR I Filed June 25, 1945 9 Sheets-Sheet 7 April 11, 1950 J. ANTOS AUTOMATIC SLIDE PROJECTOR 9 Sheets-Sheet 8 Filed June 25, 1945 [n ven {or A ril'll, 1950 Amos 2,503,239

- AUTOMATIC SLIDE PROJECTOR Filed June 25, 1945 9 Sheets-Sheet 9 lnvenfar Patented Apr. 11, 1950 AUTOMATIC SLIDE PROJECTOR Joseph Antos, Aurora, 111., assignor of one-sixt to James D. Benbow, Aurora, Ill.

Application June 25, 1945, Serial No. 601,466

23 Claims. (CI. 8828) My invention relates to a new and novel means of supporting in a container a stack of slides above the projecting lens and automatically releasing them one at a time to be projected on a screen and, after being projected, releasing the projected slide and placing same in another slide container in the same sequential order.

Most of the slide projectors heretofore offered to the public have required a raising, lowering or sidewise moving device to place the slide into a projecting position, which caused considerable wear and tear on the slides. My automatic projecting device prevents in a great measure the above-mentioned wear and tear by having gravity deposit the slide into a projecting position and, after projection, gravity will also deposit the slide in position to be pushed into the lower container.

Another object of my invention is to provide means to support a movable slide container above the projecting lens and to provide means to remove the slides one at a time from the container and provide guide means to cause the slide to fall horizontally and tilt vertically to the projecting position, and after being projected, to automatically drop into a receiving container in the same sequence as projected.

Another object of my invention is to provide means whereby the operator can cause the slides to change at will.

Another object of my invention is to provide the automatic operation of the slide changing unit by the use of sound to automatically change the slides in the slide changing unit by synchronizing the sound reproducing unit with the changing of the slides.

Another object of my invention is to combine the automatic timing, the manual operation and the remote control of projecting and changing slides in one projector, thus permitting the operator to make the selection at the same time of projecting the slides and thereby not be compelled to have attachments.

Another object of my invention is in the means whereby projecting and changing of the slides can be shifted from automatic to manual, to remote control, or coupled to a sound reproducing unit where a voice commentary or music, or both, recorded on a recording medium such as a disc,

wire, or film, will automatically cause the slide changing unit to operate at the proper intervals. Anotherobject of my invention is to provide a slide changing unit as a separate part that can be adapted for use in connection with slideprojectors now on the market.

Another object of'my invention is to provide a novel form of slide container, which can be used on top of the projector for feeding the slides, and another container of the same design can be placed below theprojecting lens for receiving shown in the accompanying drawings, and while I have shown therein preferred embodiments, I wish it understood that the same are susceptible of modification and change without departing from the spirit of the invention.

Referring to the drawings:

Figure 1 is a perspective View of the complete projector, with both slide magazines, in place and in an operative position. I

Figure 2 is a perspective View of a slide magazine loaded with slides.

Figure 3 is a perspective view of the cover for slide magazine.

Figure 4 is a perspective viewof an empty slide magazine.

Figure 5 is a perspective View of magazine slidable end gate.

Figure 6 is a top view of projector with cover removed. 1

Figure 7 isa wiring diagram of the electrical system of the projector. Figure 8 is the position of-mercury switch and arm while engaging cam.

Figure 9 is a side View of projector slide chang-.

ing mechanism with projector case cut away.

Figure 10 is a cross section thru |0|0 of Figure' 6. Figure 11 is a sectional view of lower slide magazine lock.

Figure 12 is section |2 l2 of Figure 9 and 10, looking toward the front of projector.

Figure 13 is a schematic picture of the slide changing mechanism, looking from the rear portion of the machine;

Figure 14 is a side view of selector dial and knob.

Figure 15 is a'top view of the slide changing:

unit in a normal position.

Figure 16 is a"vertical cross sectional view of Figure 15 .at l 6l6.

Figure 17 is a top view. of. slide changing innit; showing bottom slide rotated to a position to.

permit the slide to drop to the projecting position.

Figure 18 is a vertical cross section of Figure 1'7 at l8l8 showing the slide dropping and in projecting position with shutter closed.

Figure 19 is a vertical cross sectional view of the slide changing unit showing a slide clamped for projecting with the shutter open.

Figu1'eu20 is anverticalcross sectional view of the slide changing unit" showing the projected slide dropped into the lower container.

Figure 21 is a vertical cross sectional view 06 the slide changing unit showing the secondslide in dropping and projecting position and the first slide ready to be pushed forward: into the lower container with the shutter closed.

Figure 22 is a vertical CIOSSLSEctiOnEll view of the slide changing unit showing the second slide clamped for projecting with the shutter open and the first slide pushed into the lower container.

Figure 23 is across sectional view-showing the slide.- changing-guniti with remotea control and a:

manually operated devicernotmotor driven;

Figure24 shows the wiring diagrarn-ot'the remote control: and the. manually'operateddevice;

Figure 25 is-a side view of Figure 1 projecting: the picture on the screenandrthe operator de-- scribingthe'picture with therpush :button control of the slide changing unit.

Figure 26 is a side view of Figure 1 projectingthe-picture and: showing that-record :reproducing sound unit attached in :positionto: automatically operate the slide changing-andsynchronize the sameavith the sound record-.-

Description The projector consistsoithree. unitsand two slidecontainers (see Figuresl, 2. 3, .4', 5, 6, 9;:10 and.12)'.

The baseor supportl has, four rubber pads. H33

mounted on the bottom to prevent scratching or.

marring polished .surfaces,..such as a table, etc.

The base or support l'has an .openingat the.

top, shaped to permit. the main body 2Lto be inserted therein and is pivotally supported bytwo.

pivot screws and an adjustable tilting screws (see Figures 10 and 12). The main body} houses and has mounted. thereon all the principal parts of the optical system and the slide changing unit. A. cover 3.forms the top portion of ..the pro jector and fits into a recess-at 1, thus formin a. lighttight connection, and is secured to main body '2 at its'forward portion by a knurled head screw 8 and at its rear portion'by knurled head screw'9; A folding carrying'handl'e I0 is fastened by rivets H to bracketsv l2, locatedontop of the cover 3 near the center of gravity, thus providing a' convenient means for carrying the projector.

The optical system ofthis'projector consists of a light bulb l3 inserted in socket I 4 (see Figures 6," Stand-:10), which is mounted on the bottom 4 of the main body 2 by any known means, such as boltslB; A shield-l8, made in a U shape of oneor more parts; is fastened to the bottom 4 by: bolt l1 and on the sides at'thegfront'byfour bolts I8; two onteach side: To the rear portion of shield 16 is attached the reflector l9. aheadof-thebulb I3 andpositioned in notches 2!! are the two condensing lenses 2 I. In the path of the projected light beamis an adjustable objective-lens 22, having a threaded portion screwed into .the main body .2 at 23.. Above the condensing lens ..is'a U,,-shaped plate. 24 fastened bybolts 25 to the shield IE to prevent light from reflect- Thebase orsupport .l is rectangular in shape, but it can be made. in any desired. shape.

Directly 1 ing upward. Between the condensing lens 2! and the adjustable objective lens 22, and extending vertically within the main body 2, is the slide changing unit indicated as 25. (See Figures 6, 9, 10, 12, 13, 15, 16, 1'7, l8, 19, 20, 21 and 22.)

On the underside of the bottom 4 of the main body 2 is mounted a motor 21, which furnishes all the motive power required to operate the automatic slide changingunit 25 and the cooling system -(see Figures 6, 9','10 and 13). The shaft 28 of the motor 2'! projects upward to the inside of the main body 2 and has mounted thereon a wormZB; upon which is attached the cooling fan 30 by means of screw 3!. The cooling fan 3!] draws cool air from the underside of the projector; causing the air to flow upward in the direction of the arrows (see Figure 10), thus cooling the light bulb l3 and the lide 32 in the projector-aperture 33, and finally pushing the air current upward to the outside of the projector thru theslots 34 in-the top ofth'ecover 3." The worm 29'dr ives the worm gear 35, which is rotatably mounted on the long horizontal shaft 36; which is supported within the main body 2'at each end by bearings 31.

Referring to Figures 12 and 13, mounted on" horizontal shaft 36'to the left of and contacting the worm gear is an eccentric 38; which is fastened to the horizontal shaft36 by set screw" 39. To the right ofthe wormgear 35 on the' horizontal shaft 35 is mounted a' slidable collar= 40'by means of either a shaft key 4| or a vertical pin in'the horizontal shaft 36, which shaft key 4! engages keyways 42 in the slideable collar 40.

At the extreme right and adjoining the side of the main body '2 on the horizontal, shaft .36" is mounted along collar 43 by'set screw 44; having a threaded portion upon which is mounted an adjustableithreaded collar 45.

One end of the compression. spring. 46' is mounted on slidable collar 40 and. the opposite end on the adjustable collar 45.

The rotation of the eccentric 38Land. the horizontal shaft 3'5 is accomplished by the friction. exerted by the worm gear 35 at the surface 41. On the outside of the main body 2 on the horizontal shaft 35 is a knurled knob 48.for manually rotating .the horizontal shaft 35 .and the eccen-' tric 38; The degree of pressure or the amount of friction exerted by the spring on the sli'dable collar-'40 and'the Worm gear 35 against the face of'the eccentric 38 at the surface 4'! is deter.- mined by adjusting the adjustable collar 45.

Due :to the friction set up at surface 41 between.

the worm gear 35 and the eccentric. 38; it is apparent that the eccentric 38 will continue to rotate with the rotation of theworm gear35 and.

asall' the slide changing operations are con-u trolledpby the rotation of the eccentric 38it is only necessarytocontrol its movements. For. this purpose a horizontal rod 49 is provided. which is supported by bearings 50 at each side of the main body 2, having one end bent to form the lever 5i. Fastened to the horizontal rod 49 with the set screw 52 is thehub of .the lever 53, which. has a hook 54 to engage the notch of the'eccentric 38 to keep it from turning.

To manually operatethetirning of the slide.

changing mechanism it is onlynecessary to dee press thelever 5| momentarily. This pullsthe hook 54 of the lever 53$ away from the notch 55 of the. eccentric 38 and permits the horizontal shaft 36and the eccentric 38'to revolve, and .at

the end of a completerevolution, the spring 55'. will force the hook 54 of the lever 53 to again engage the notch 55 of the eccentric 38. If the lever 5| is held depressed for any length of time, it will permit the eccentric 38 to revolve'until the lever 5| is raised, and thus the operator can control the number of slides he wishes to be passed without showing.

The time interval of the projection of each slide can also be controlled electrically by a special mercury switch I3 of such construction as is shown in Figures '7, 8, 12 and 13, which is mounted on the inside of the main body 2 and is controlled by the position of the selector knob 58 on the dial 59, located on the outside of the main body 2 (see Figures 1, 6, 12, 13 and 14) A lever assembly 60, consisting of a vertical lever 6| and a horizontal lever 62 having a pawl 63 pivoted to the vertical lever 6| by bolt 64, is rotatably mounted on the horizontal rod 49. The lever assembly 60 has a continuous rocking movement, due to the contact of the horizontal lever 62 on the cam 65, which is a part of the hub of the worm gear 35. During the rocking movement of the lever assembly 60, pawl 63, which engages the teeth of the ratchet wheel 66, will rotate the step cam 61, which is a part of the ratchet wheel 66 (see Figures 7 and 13)'. The step cam 61 and the ratchet wheel 66 are rotatably secured to the inner side wall of the main body 2 thru the bearing screw 68 and the spring cup washer 69. The spring cup washer 69 applies sufficient frictional drag to the ratchet wheel 66 and the step cam 61 so that they will stay in a stationary position during the rearward stroke of the pawl 63.

Attached to the same side of the main body 2 by pivot screw I0, directly ahead of the step cam 61, is avertical arm H, the upper end of which has a socket 12 in which is inserted the mercury switch 13. The normal position of the mercury switch I3 is tilted so that the two electrodes I4 and '15 are above and away from the mercury I6. As the step cam 61 is rotated forward with the consecutive strokes of the pawl 63, the mercury switch I3 and the lever or vertical arm 'II are likewise moved forward against the tension of the spring 11 until the step cam 61 passes the hook I8 of the vertical arm 'II, causing vertical arm II and mercury switch I3 to rapidly snap backward, and the mercury 16 in the mercury switch I3, due to momentum, will roll up the incline and momentarily cover the two electrodes 14 and 15, closing the circuit and energizing the coil I9, which is attached to the forward part of the bracket 80. The magnetic field of the coil 19 will attract and pull the lower end of the lever 53 forward against the spring 56 and disengage the hook 554 from the notch 55 and permit the eccentric 38 to follow the rotating of the worm gear 35 in the manner heretofore described.

Directly behind the vertical lever 6|, a cam 8| is connected to the selector knob 58 and held in a fixed position thru the spring 82. The cam 8| controls the length of the back stroke of the pawl 63, thus lengthening or shortening the slide changing intervals. With the high side of the cam 8| turned all the way back, as shownin Figure 7, the pawl 63 is allowed to travel its maximum distance, contactin each time as many as five or six teeth of the ratchet wheel 06, and thus permitting the minimum time interval between slide changes. As the cam 8| is rotated forward by means of the selector knob 58, the time interval between slide changes is increased until, when the cam 8| is turned directly forward toward the vertical lever 6|, movement of the pawl 63 is prevented and the slide changing ceases to be automatic.

The projector is then in a non-automatic position and operable only by depressing the lever 5| as heretofore described, or by using the extension cord 83, shown in Figures 7 and 25, and depressing the button 84 in switch 85. The extension cord 83 is connected to the projector thru the plugs 86 and 81. Sometimes it is desirable for an operator of the projector, especially when giving a lecture, to stand beside the screen and point out various points while facing the audience, changing the slide images by the operation of the switch 85, as shown in Figure 25.

The wiring arrangement is such as that shown in Figure 7. The plug 88 receives all the power, the switch 89 connecting the light bulb I 3 and the switch 90 controlling the motor 21.

At the top of the slide changing unit 26 (see Figures 10, '16, 18 to 22) is a separating and rotating plate 9 I, circular in shape and having a square hole 92 in the center thereof, which rotates about 45 degrees on the surface plate 93. The socket 94 is recessed to form a guide and permit the rotation of the separating and rotating plate 9| and is fastened to the surface plate 93 by four or more screws 95. The socket 94 has a square hole 96 to receive the slide container 98 and has a ledge 91 to prevent the slide container 98 from dropping onto the separating and rotating plate 9|. The socket 94a can be made adjustable for receiving slides of various thicknesses by making it in two parts and threading the upper part 99A and the lower part 99, as shown in Figures 9, 12 and 13. The socket 94 is positioned so that the square hole 96 is substantially 45 degrees out of line with the square hole I00 in the surface plate 93. The socket 99 and 99A is set to accommodate the standard thin paper mount slide. However, if glass mounted crother thicker slides are used, it is then only necessary to release the spring clip IOI, which contacts the notch Hi2, and rotate the socket 99A one or more counterclockwise turns to provide proper clearance for the thickness of the slides to be shown.

The separating and rotating plate 9I is normally positioned so that its square hole 92 is in line with the square hole 96 of the socket 94, thus permitting the lower slide 32 in the slide container 98 to drop into the square hole 92 of the separating and rotating plate 9| and rest on the surface plate 93, as shown in Figures 12, 13, 15 and 16.

The slide changing unit 26 is supported by the bottom. 4 of the main body 2 and has two spaced apart parallel plates I04 and I05 flanged at the lower end. Each plate is attached to the bottom 4 by two screws I06. The upper ends of the vertical plates I04 and I05 are attached to the surface plate 93 by welding or any other means, which in turn supports the socket 94 for receiving the slide container 98, which holds the slides (see Figures 1, 10,16, 18, 19, 20, 21 and 22).

At the lower end and between the plates I04 and I05, on top of the bottom 4, is an opening I01 to receive the lower slide container 98, into which the slides drop after they have been projected. Attached to the bottom 4 at the opening I0! is a spring steel positioning clip I08, which, with a riveted pin I09, engages the positioning hole H0 in the slide container 98, thus insuring a proper alignment between the notches I I I in the slide container 98 and the guideway H2 in the slide changing unit 26.

The vertical plates I04 and I05 are spaced apart by the ,wall 1H3, which is bent forward :at light angles at the bottom to form a top for the opening I01 and extends upward vertically and then curves forward to for-m a ledge H4 and is connected to front ,edge of the slide receiving hole N0, of the surface plate 93. On the inner and rearward portion of the vertical plates I04 and I05 are fastened guide bars H5 and H6 and the lower front edges face and extend parallel to the aperture 33, above which they curve rearward-to stop at the rear edge of the slide receiving square hole I00. To form the guideways I I2, guide bars I I5 and I I6 are connected or fastened to the vertical plates I04 and I05, or they can be of a one-piece casting as shown.

Thus it will be seen that we have a guideway H2 substantially square at the top to receive a slide 32 in a horizontal position, narrowing down to -a position in the vicinity of the aperture '33, where it is only slightly wider than the thickest slide ever used. The rotation of the separating and rotating plate 9! will remove one slide at a time from the bottom of the stack of slides in the upper slide container 98 and the separating and rotating plate 9| will rotate to the position shown in Figures 1'7 and 18, thus permitting the slide 32 to be released at the receiving hole I00. A single slide, after being released at the receiving hole I00, will fall horizontally until the front edge contacts the ledge I I4. Then the rear edge will swing downward by gravity, being guided by the curved edges of the guide bars H5 and H6 (see Figures 10, 16, 18, '19, 20, 21 and 22) to a vertical-position in the lower and narrow position of guideway H2.

Directly on the outside of the vertical plates I04 and I05, yoke H8 is pivotally mounted at its upper end to vertical plates I04 and I05 by pivot screws and bushings H9 or shoulder screws, and at its lower end is attached a flat slide-ejecting pad I20. Fastened to the slide ejecting pad I by pin I2I is connecting rod I22, operated by eccentric 38. On both sides of the yoke H8 are screw studs I23, which pass-thru slots I24 of the guide bars I I 5 and I I6 and vertical plates I04 and I05 to pivotal y support the slide positioning frame I25, located between the guide bars H5 and H6. Directly above the slide positioning frame I25 is located the trip latch I26, which is pivotally mounted by a pin or stud 51 to guide plates I I5 and-I I6.

The slide positioning frame I25 is U-shaped and has an opening I28 to conform and coin ide with the aperture 33. The lower edge of the slide positioning frame I25 has a right angle lip I29. The purpose of "this slide positioning frame I25 is to catchthe first slide 32 released by the separating and rotating plate 9| by-the lip I29, which projects through an opening I42 in the wall I I3, and hold it tightly and perfectly-still in the projecting position (see Figure 19). Trip latch I26 engages the notch I21 in the top of the'slide positioning frame I25 and the spring I30 is attached to the lower portion of the yoke H8 and to the rear of the U-shap ed portion of the slide positioning frame I25. On the left hand side of the slide changing unit 26 is-alever I3I connected to the separating and rotating plate 9I at I32 and pivoted to the lower flanged portion of the vertical plate I04 at I33. On the same side and attached to the yoke H8 by the screws I23 and I34 is a bracket I35, having flanges I36 at the top and I331 at the bottom. The bottom flange I31 of the bracket I has. a notch I38 to engage and oscillate the lever I 3I,-whi cl1, in

8 turn :rotates the separating and rotating plate 9I approximately 45 degrees forward and backward.

The shutter I39 is made of opaque or semiopaque material and is attached to the rod I40, which is mounted in the vertical plates I04' and I05 directly above the aperture 33 in front of the wall H3 between the vertical plates I04 and I05. The rod I40 extends outside of the vertical plate I04 and is bent on one end to form a lever I, which contacts the top flange I36 of the bracket I35 to raise and lower the shutter I39 during the oscillating movement of the yoke H8.

On the top of the right angled portion oi. the wall H3 at the opening I01 between the vertical plates I04 and I 05 is mounted by the rivet I44 for'up and down movement an upper slide retainer I43, having the inner portion made in a V shape. At the bottom of the opening I01 ,is the lower slide retainer I with an upward projecting lip mounted between the vertical side plates I04 and I05 for rotative movement by the pin I46, supported by the vertical plates I04and I05. On the under side of the lower slide retainer I45 is a spring I41 supported by the bottom 4 to keep the lower slide retainer I45 in a normal position.

The movement of the lower slide 32 by the ejecting pad I20 from the position shown in Figure 21 to the position shown in Figure 22 will cause the upper slide retainer I43 to moveupward and the lower slide retainer I45 to depress the spring I41. When the lower slide 32 is in the position shown .in Figure 22, the upper slide -retainer I43 and the lower slide retainer I45 will return to theirnormal positions and hold the slide 32 in an upright position in the lower slide container 98.

Referring-to Figures 1, 2, 4 and 5, the slide container 98 can be made to any desired length to hold any number of slides 32, usually to 150. The slide container 98 as shown is made square, but it-can be made to suit the dimensions of any size slide which is to be shown or projected. The slide container 98 as shown is made in a U shape, having the top edges and one endflanged to assistin retaining the slides 32 in a proper position. The notches III in the top flanged edges are to permit the slides 32 to drop vertically into the slide container 98 when they are placed in the opening I 01 to receive the slides 32 after having been projected. The notch I83 is .to provide room for the lower slide retainer I45 to move up and down. On the bottom of the slide container 98 there is a circular positioning hole .IIO to permit the positioning pin I09 to hold theslide container 98 in its proper location in the opening I01 to permit the slide 32 to drop into the lower slide container 98 through the notches I I.

The end gate I I1 is made in a U shape of spring steel, or some other metal, and the sides are bent slightly outward from a right angle to cause friction against the sides of the lower slide container 98 when used for receiving the projected slides 32.

When it is desired to operate the slide projector with the automatic slide changing unit 26, we take the slide container 98, which has been loaded with the slides 32, and remove the end gate H1 in the opening 96 of the socket 94 against the ledge 91, and place an empty slide container 98, with the end gate II 1 against the ejecting pad I20, in the opening I01 to receive the slides 32 after they have been projected (see Figures '1,

10,- 15, 1'8, 17, 18, 19, 21 and 22). I then connect the power line with the plug 88 of the slide projector and set the knob 58 on the dial 59 at the slide changing speed desired (see Figures 1, 6, 12, 13 and 14) The lower slide 32 in the upper slide container 98 will drop into the square opening 92 of the separating and rotating plate 9I (see Figures 10, 15 and 16 for the normal position). Then set the lamp switch 89 and the motor switch 90 in the on position. This will start the rotation of the motor 21 and the light bulb I3 will light. As the motor 21 rotates (see Figures '1, 8, 12 and 13) the worm 29 will rotate the worm gear 35 and the cam 85, causing a rocking movement of the lever 80, and the pawl 63 engages the ratchet wheel 86 and rotates step cam 81, which is a part of the ratchet wheel 86, until the time interval set by knob 58 has been reached. Then the vertical arm 1I will rapidly snap backward and cause the mercury 18 in the mercury switch 13 to roll up the incline and momentarily cover the two electrodes 14 and 15, closing the circuit and energizing the coil 19 (see Figures 9, l0 and 13), which will pull the lever 53, releasing the hook 54 from the notch 55, and permit the eccentric 38 to rotate and pull backward on the connecting rod I22, the ejecting pad I20 and the yoke H8, thus causing the bracket I35 to oscillate the lever I3I and move the separating and rotating the slide 32 to drop vertically into the guideway I I2 to the projecting position (see Figures 11 and 18). The continued rotation of the eccentric 38 moves the connecting rod I22, slide ejecting pad I20, the yoke I I8 and the lever I3I to the normal position (see Figures 15, 18 and 19). Thus the slide 32 is clamped into the projecting position and the shutter I39 is opened to permit the projection of the slide 32 on the screen.

After the slide 32 has been projected on the screen I11 and the desired time for projection has elapsed, the continued operation of the worm ear 35 and the movement of the ratchet wheel 88 will again cause the step cam 81 to rotate until the vertical arm 1I snaps backward, causing the mercury switch 13 to again energize the coil 19 and pull on the lever 53, which releases the hook 54 from the notch 55 and Permits the eccentric 38 to rotate and pull backward on the connecting rod I22, the ejecting pad I20, the yoke II8 to the position shown in Figure 20, and the screw I 23 will move the slide positioning frame I to an open position (see Figure 20) and the projected slide 32 is permitted to drop into the lower slide container 98 and the shutter I39 is closed. By the continued rearward movement of the yoke .I I8, the connecting rod I22 and the ejecting pad I20 to the position shown in Figure 12, the screw I23 and the spring I will cause the trip latch I28 to release the positioning frame I25, which will assume the tilted position shown in Figure 12 and thus receive the new slide 32, which has just been released by the rotation of the separating and rotating plate 9 I.

By further rotation of the eccentric 38, the new slide 32 is clamped in position and the released slide 32 is pushed forward into the lower slide container 98, as shown in Figure 22, and the end gate H1, in cooperation with the upper slide retainer I43 and the lower slide retainer I45, keeps the projected slide 32 in an upright position. This 10 procedure is continued until all the slides 32 in the upper slide container 98 have been projected and filed inthe lower slide container 98 in the same sequence as projected.

Description of the synchronizing of the sound reproducing unit and the projector with the slide changing unit Figure 26. shows a standl51, which supports the projector I56 and the slide changing unit 26 (as previously described) and underneath the projector I58 and the slide changing unit 28 is a sound reproducing unit I58, which is synchronized with the slide changing unit 28 to automatically change the slide 32 at the proper time to corelate the subject matter of the sound record with the subject matter of the slides 32.

A conventional type of sound reproducing unit I58, consisting of the conventional amplifier I59 with the loud speaker I14, and a tone arm I60, a turntable I6I with a. vertical shaft I83 connected thereto in the center thereof, centralizes the sound record I16, and the shaft I83 projects downward underneath the turntable I8I and has mounted thereon a worm I64. The shaft I63 is supported for rotation by a bearing I8I at the bottom of the reproducing unit I58. A motor I62 is mounted underneath the turntable I6I and rotates the turntable I6I, the vertical shaft I63 and the worm I64. The worm I84 has engagement with the worm gear I66 and the step cam I65, which are assembled together and are mounted for up and down movement on the horizontal shaft I13.

The mercury switch I61 attached to the arm I68 is pivotally mounted on a horizontal shaft I89. The cam pin I12 is attached to the arm I68 and is held in contact with the step cam I65 by spring I10, attached to the arm I88, and the underside of the sound reproducing unit I58. The arm I88 could also be mounted above the step cam I85. The motor I 62 of the sound reproducing unit I58 and the projector power plug 88 are connected to a common power receptacle I15. The projector plug 81 is connected to the mercury switch I61 leads. The step cam I65 can be made with more than one step I1I if desired, depending on the length of time required to reproduce the sound description of the slide 32, which is being shown by the projector I56. The location of two or more of the steps HI and the size of the worm gear I65 can be arranged to vary the time of changing the slide 32 to suit the amount of time required to complete the description of the slide 32 being shown.

When it is desired to reproduce the sound description of the subject matter shown on the slides 32 to be projected on the screen I11, I connect the power plug 88 of the projector I58 (which includes the slide changing unit 26) by power supply cord I18 to receptacle I15, and the motor I82 by power supply cord I19 to receptacle I15. I then move the power switches 89, 90 and I to operating positions, which will light the lamp I3 and start the projector motor 21 and the sound reproducing motor I82. When the motor I82 starts to rotate the turntable I8I and the sound record I16, it also rotates the vertical shaft I63, the worm I64 and the worm gear I66, causing the step cam I65 to rotate therewith and when the step I H is opposite the cam pin I12, it will be forced upward by the spring I10 with a quick motion, which will cause the mercury in the, mercury switch I61 to make contact with the electrodes andfenergize the coil 19 of the projector I56 andppeijate the slide changing unit 28, permitting th s d w ch has b en s wnztodnopzinto t e lower ;slide container 98 and anotherjslide .32 to fall into the projection position as previously described.

As the rotation of thesound record I16 continues, the slides 32 willbe changed attheproper intervals, in accordance with the 1timelimit previously determined and arranged for'by the steps :11" of the step cam I65 and the said sound record 116. The slide changingunit '26-can'also be -con trolled by the operator 'by the :use of a remote control push button,,as shown-in Figure .25.

Another and more simplified meansof controllingthe operation of "the. slide changing .unit 26 of the projector, either manually .-or by remote control, is shown in Figures 23 and 24. 'Here .I show the projector previously described, but ,less certain parts. I omit the following parts:

Nu e

21-motor 29-worm 30-fan 3Iscrew 35-worin gear Si -horizontal shaft 38--,eccentric 40-slidable collar 4 Ishaft key 43--l0ng collar 4 -adjustable threaded collar 46--spring 48knurled knob 49--horizontal rod 53--lever 56spring 58,selector knob 60.-lever assembly 63--pawl 66ratchet wheel 6'Istep cam 68bearing screw 69spring cup washer 'I0pivot screw II-vertical arm 'I3-mercury switch IL-spring IS-coil Bil-bracket 8 Icam 82-spring And substitute these:

I 48-pin I 4 9plunger I 50-shoulder I 5 Istem I 52spring I 53shaft I 54--lever I55--forked lever I 8 2 solenoid By remote control I produce the forward and backward movement of the yoke I I8 and the ejecting pad I20, which operates the slide changing unit 26 for the changing of the slides 32. A solenoid I82 is mounted at the rear of the ejecting pad I20 by the pin I48 to the side of the shield I6, and a movable plunger I49 is fitted within the core of the solenoid I82. The front part of the movable plunger I49 is turned down to form a shoulder I50 and a stem I5I is connected to the ejecting pad I20 by the pin I 2I. The spring I52 is located within the core of the solenoid I82, which attracts the movable plunger I40, causing main body 2.

the ejecting pad I20 and the yoke I I8 to'bemoved rearward. Releasingthe button 84 of the switch 85 de-energizes the solenoid ;I82 and-permits the spring I52 to push the .movableplunger I49 forward, thus completing the rearward andforward movement of the ejecting pad I20 and the yoke H8, which causes the changing of the slides '32 as heretofore described.

For manual operation of .the projector (see Figiues 23 and 24), a shaft I53 extends crosswise and is pivotally supportedby the side wallsofzthe The shaft I53 at one end, outside of the main body 2, is bentat right angles, forming the lever I54, and attached to the shaft I53 is an upstanding forked lever I55, the forked end of which engages the shoulder I50 of the movable plunger I49. By depressing the lever 1154, the movable plunger I49 will cause the ejecting pad I20 and the yoke II8 to move rearward and compress the spring I52, and by releasing the lever I54, the spring I52 will cause the ejecting pad I20 and the yoke II8 to move forward, thus changing the slides 32 as desired.

This manual and remote control shown in Figures 23 and 24 can be used separately or in combination.

The slide changing unit shown in Figures 23 and 24 can be used for changing the slides in connection with the slide projectors now on the market, providing there is enough space, or it can be changed to have enough space between the condenser lens and the projecting lens. The simplified form of the slide changing unit, as shown on Figure 23, can be made to automatically operate in conjunction with the sound reproducing device shown in Figure 26. When the sound fihn record or wire has reproduced the description of the slide being shown, electrical contact will automatically be made with the solenoid I82 and the stem I5I will be moved and the slide 32 just shown will drop into the lower slide container 98. The slide changing unit 26 will revolve approximately 45 degrees and permit the next slide 32 to drop to the projecting position. This will be repeated until the sound reproduction has been completed and the slides 32 in the upper slide container 98 which relate to the sound reproduction have been shown. This combination will be automatic.

Having thus described my invention, what I claim as new and useful and desire to secure by Letters Patent is:

1. In a slide projector, in combination, an automatic slide changing device having a substantially vertical guideway with a square opening at the top tapering to a rectangular shape at the bottom, a socket having a square opening attached to the top of said guideway and the square openings in said guideway and said socket being out of alignment, a rotating plate having a square hole mounted for rotating movement in said socket above said guideway, a U-shaped member attached to the sides of said guideway for oscillating movement having a slide ejector attached to the lower portion of said U-shape member, an oscillating member mounted on one of the sides of said guideway and attached to said rotating plate, a bracket attached to one side of the said U-shape member contacting said oscillating member, duplicate slide containers, one inserted vertically in the top of said socket to feed said slides to said socket and the other in a horizontal position at the bottom of said guideway to receive the projected slides, a slide positioning frame on the inside of the sides of the said guideway and attached to said U-shape member, a ratchet mounted on the inside of the sides of said guideway to engage said slide positioning frame, means to cause forward and backward movement to said slide ejector and said U-shape member to oscillate said oscillating member and rotate the said rotating plate to remove one slide at a time from said socket and the upper slide container and permit gravity to cause the said slide to drop to the projecting position, and after projecting said slide to permit the slide to drop by gravity into the lower slide container in front of said slide ejector and by the forward movement vof said slide ejector to move said slide in said lower slide container.

2. A slide changing unit to be used in connection with a slide projector, consisting of a vertical guideway having a square opening at the top tapering to a rectangular shape at or near the center, a socket having a square opening of the same dimensions as guideway mounted at the top thereof for receiving an upper slide container, rotating means having a square opening the same size as said socket mounted between said socket and said guideway, a U-shape member having a slide ejector on bottom mounted on the sides of the guideway for oscillating movement, a slide receiving and positioning member mounted on said U-shape member and suspended in said guideway near the center thereof, an attachment at the lower end of said guideway to receive a lower slide container for projected slides, a vertical member having one end mounted on the lower end of said guideway and opposite end attached to said rotating means, means to oscillate the said U-shape member to rotate said rotating means and remove one slide at a time from said upper slide container to permit said slide to drop to a projecting position and after projecting to drop into the lower slide container in the same sequence as projected.

3. A slide projector, in combination, a slide changing unit having a substantially vertical slide guideway, a socket attached to the top of said guideway for supporting an upper slide container having a vertical stack of horizontal slides therein for gravity feeding, a rotating and separating plate mounted in said socket under said container to remove one slide at a time from said container to permit said slide to drop horizontally onto a ledge in the upper forward portion of said guideway causing said slide to tilt and drop vertically to a projecting position in a slide positioning frame of said guideway, a horizontal opening under the bottom of said guideway to receive a lower slide container, means mounted on said projector and slide changing unit to rotate said separating and rotating plate to remove one slide at a time from said container and permit said slide to drop vertically to the slide positioning frame in said guideway for projecting, and after projecting to cause said slide positioning frame to release and drop said projected slide into the lower container, mean to push the projected slides forward into the lower container, upper and lower latch means in said opening to hold the said slides in a vertical position in same sequential order as projected.

4. A slide projector, in combination, an automatic slide changing unit as of claim 1, sound reproducing units having sound records describing the subject matter of the slide to be projected, automatic control means mounted on the slide projector connected to said slide changing unit and sound producing unit to automatically rotate the rotating plate to change the slides by the sound records.

5. A slide projector, in combination, an automatic slide changing unit as of claim 1, means mounted on said slide projector and automatic slide changing unit to predetermine the amount of time allowed for projecting said slides on the screen.

6. A slide projector, in combination, a slide changing unit as of claim 1, means mounted on said slide changing unit at the control of the operator to predetermine the length of time for projecting the slides.

'7. A slide projector, in combination, with a slide changing unit as of claim 1, a remote control device connected to said slide changing unit to permit the operator to control the changing of the slides and to determine the length of time for projecting the slides on a screen.

8. A slide projector, in combination, an automatic slide changing unit of claim 1, an adjustable timing device having a knob and a dial mounted on the side of the projector connected to said automatic slide changing unit, rotation of said knob on said dial toward the right or left determining the amount of time to be consumed in projecting and changing each slide and will automatically continue at the same speed until the operator turns the knob to a different position.

9. An automatic slide changing unit as of claim 1, a slide container made in a U-shape having the two top edges and one end flanged, said slide container having notches in one end of the top flanges to permit the projected slide to drop into the container, a U-shape friction plate at the forward end to hold the projected slides upright and to move endwise in the container with the projected slide after each projection.

10. In a slide projector, in combination, a slide changing mechanism with an approximately vertical guideway, a removable slide container mounted vertically at the top of said guideway, a rotating plate having an opening therein same size as said slide mounted for rotation under said container above said guideway, said slide container mounted at an angle with said guideway, means to rotate said rotating plate to aline said slide with said guideway to permit said slide to drop horizontally into said guideway and tilt vertically to the projecting position, a removable lower slide container mounted under said guideway and the projecting lens to receive said slide after projecting, means attached to said projector to rotate said rotating plate and remove one slide at a time from said upper container and after projecting to permit said slide to drop into said lower slide container in the same sequence as the slides were in the upper container.

11. A slide projector, in combination, a slide changing unit having a substantially vertical slide guideway with an opening the same size as the slide to be projected and tapered to a rectangular shape at the projecting position, a socket adjustable for slides of various thicknesses attached to the top of said guideway for supporting a removable upper slide container having a vertical stack of horizontal slides therein for gravity feeding, a rotating and separating plate mounted in said socket under said container to remove one slide at a time from said container to permit said slide to drop horizontally onto a ledge in the upper forward portion of said guideway causing said slide to tilt and drop vertically to a projecting position in a slide positioning frame messes ofisaid guideway, a horizontal opening under the bottom of said guideway to receive a removable lower slide container, means mounted on said projector and slide changing unit to rotate said separating and rotating plate to remove one slide at a time from said upper container and permit said .slide to drop verticallyto the slide positioning frame in said guideway for projecting, and after projecting tocause said slide poistioning frame to release and drop said projected slide into the lower container, means to push the projected slides forward into said lower container, upper and lower latch means in said opening to hold the said slides in a vertical position in same sequential order as projected.

12. A slide projector, in combination, a slide changing unit consisting of an approximately vertical slide guideway having an opening at the top the same size as the slide tapering to a rectangular shape at the projecting position mounted in said slide projector between the condenser and projecting lenses and extending upwardly through the top of slide projector, a removable upper slide container mounted above and at an angle withthe upper end of said guideway, means at upper end of said guideway to permit adjustments for slides of various thicknesses, horizontal rotating means in theupper. end of said guideways under said upper container toremove a single slide from said upper container and align said slide with said guideway to permit said slide to drop by gravity to a vertical projecting position and after projectingto release said slide to permit it to drop by gravity into a lower container duplicate of the upper container under the lower end of said guideway, means to open and close avshutter during the changing of the slides, means operatable with said horizontal rotating means to push the projected slides forward in said lower container and means inpsaid lower container to retain said slides in the same sequential order as projected.

13. A slide projecting machine having a frame and condensing and projecting lenses, in combination, a vertical slide changing-unit having a slide-guideway mounted in said projecting machine between said condensing. andwprojecting lenses, a removable upper slide container having a vertical stack of horizontal slides therein mounted vertically on the top of said slide changing unit, a horizontal rotating plate having an opening to receive one slide at a time rotatably mounted at the upper end ofsaid slide changing unit undersaid slidecontainer, power means mounted on said1 frame. operatively connected to said slide changing unit and said-rotating plate, control meanspn said frameto control the power means to cause the rotation of said rotating plate to remove. said slides one at a timefrom said upper slide container to; permitsaid slide to drop by gravity horizontally and thenvertically in said guideway to the projecting position andafter being projected to drop into another removable slide container duplicate of the upper slidecontainerunder said guideway. in same sequence as they were in said upper slide. container.

14. A slide projector, in combination, aslide changing unit having a substantially vertical slide guideway, a socket attached to the top of said guideway for supporting an upper-slide container having'a vertical stack of horizontal slides therein for gravity feeding, arotating and separating plate mounted in said socket under saidcontainer to; removeone slide at a time fromsaidncontainer to permit said slide to drop horizontally; onto-a able means to permit the use of slides of various 16 ledge-in the "upper forward portion of said guide way causing said slide to tilt and drop vertically to a projectingposition into a slide positioning frame ofsaid guideway, a horizontal opening under the bottom of said guideway to receive a lower slide container, an electric motor mounted onsaid-projector and slide changing unit to '-ro-'- tate. said separating and rotating plate to remove one sli'de at a time'from said upper container-and permit said slide to drop vertically to the slide positioningfram'e in said g-uideway-for projecting; and after projecting to cause said slide position ing frame to release and drop said projected slide into the lower container, means to push the projected slides forward into the lower container, upper andlower latch means in said opening-to hold the said slides in a vertical position in same sequential order as projected, control means at tached tosaid projector and slide changingunit to control the-rotation ofsaid electric motor-to permit the operator to change the slides at will.

15. In aslide projector, in combination, a slide changing mechanism with an approximately vertical guideway, a removable upper slide container having a vertical stack of slides mounted vertically at the top of said guideway, a rotating plate having anopening therein slightly larger than the size of said slides mounted for rotation undersaid container above said guideway, said slidecontainer mounted at an angle with said guideway, means to rotate said rotatin plate to aline said slides with said guideway to permit a single slide at a time to drop by gravity horizontally. into said guidewayand tilt vertically to the projecting position, a shutteroperatively connectedto saidrotaryplateto block out the light when changing slides, a removable lower slide container duplicate I of the upper slide container mounted under said guideway and the projecting lens to receive said slides after projecting, electrical means attached to said slide changing mechanism and slide projector to rotate saidrotatin iplate to control said shutter and remove one slide at a time from said upper slide container and after projecting to permit said-slide to-dropinto said lower slide container in the same sequence as the slides were in the upper slide container, an automatic timing device attached to said slide changing mechanism and said electrical means, control means on said automatic timing device which can beset by the operator at a-predetermined time limit for the projection of said slides.

16. Inza slide projector, in combination, a slide changingmechanism having a substantially vertical slide guideway with an opening at the top, slightly larger than the size of the slides to be projected and tapered "to a rectangular shape at the projecting position, a socket having adjustthickness attached to the top of said guideway for.vertically supporting a removable slide container. to hold and to permit gravity feeding of slides to be projected, means under said container to remove one slide at a time and permit-said slide to drop vertically to the projecting position, means to' permit said projected slide to drop into a horizontally positioned duplicate slide container located under said projecting position, means 'mounted on the said projector and slide changing mechanism to remove one slide at a time from" said-upper=containerand drop vertically to projecting position and after being projected w release and drop-saidslide into said lower horizontat container having means therein to hold 

